Recent content by Methavix

  1. M

    Critical mass for nuclear fusion

    Thank you! Actually, I'm considering this kind of bombs for advanced space propulsion systems, not on the Earth. Anyway thanks for your suggestion.
  2. M

    Critical mass for nuclear fusion

    Oh yes, I didn't mean that I'm working on this kind of fusion bomb :D I only meant that I am considering this system of ignition in the reasoning I am doing with other people. Thanks for your help!
  3. M

    Critical mass for nuclear fusion

    Thanks! In this case we are considering the ignition with a laser or relativistic electron beam, so is it true that we can have a micro-bomb according to you?
  4. M

    Critical mass for nuclear fusion

    Hello, can you please confirm this statement "Nuclear fusion does not require a minimum mass to occur (critical mass), which is instead a characteristic limit of fission. So you can make small fusion bombs as much as you want."? Thanks!
  5. M

    Temperature of a radioactive material

    Ok, I understand the error :) Now I am supposing to have about 1 ton of Na-24 (2.4*10^28 atoms). I imagine that it is again a huge quantity, but it is just an exercise. The most important thing is that now I am using right equations, thanks to your suggestions. Thanks
  6. M

    Temperature of a radioactive material

    Thank you. In my calculation I supposed to use Na-24 (half life of 15 hours). I didn't think that radioactive materials was so hot because to the decay itself.
  7. M

    Temperature of a radioactive material

    Thanks a lot mfb and Chestermiller! I will use the equation corrected with the term suggested by Chestermiller and with a smaller value of mass. Regards
  8. M

    Temperature of a radioactive material

    Yes, too much power :) But I didn't know if the error was the equation I used or the problem is too much material. So you are saying that the problem is too much material, right? I have to reduce the total mass in order not to reach this power. Is the equation I have used in my previous message...
  9. M

    Temperature of a radioactive material

    Sure :) E = 8.874*10^-11 J (or about 553.88 keV) lambda = 1.287*10^-5 1/s S = 175 m^2 N0 = 1.2577*10^30
  10. M

    Temperature of a radioactive material

    If I use power instead energy, for radioactive decay I have: [N0*lambda*exp(-lambda*t)]*E where N0 is the total number of atoms of that body and lambda is the decay constant. Now can I say? that: sigma*T(t)^4*S = [N0*lambda*exp(-lambda*t)]*E If this equation is correct I can easily calculate...
  11. M

    Temperature of a radioactive material

    N is changing rapidly, in general. I have done the integration because Stefan-Boltzmann law gives a power (energy/time), but to calculate the temperature I need an energy balance. So to convert power in energy I have done this... Is it wrong?
  12. M

    Temperature of a radioactive material

    Hello people, I have again doubts about the same problem. The radioactive body releases this energy: N(t)*E where N(t) is the number of decayed atoms as a function of time, and E is the energy released by each atom. I consider a black body in vacuum and I write the energy balance this way (I...
  13. M

    Temperature of a radioactive material

    Yes, I know this. Thank you.
  14. M

    Temperature of a radioactive material

    As you say I easily can have the total energy produced by electrons (because of the decay), but how can I calculate the equilibrium temperature (as a function of time)? I should consider also the black body radiation, right?
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